Written By Geraldine Matchett, Chair of the GHG Protocol Steering Committee

On September 9, 2025 GHG Protocol and the International Organization for Standardization (ISO) announced a ground-breaking partnership, aimed at reducing fragmentation in the GHG accounting landscape. This new partnership drives forward an ambition of harmonization and co-development, resulting in a  common global language for emissions measurement and reporting and thus simplifying the task at hand for companies, consultants, verifiers, auditors, conformity assessment bodies, and other third parties (e.g., trainers and software companies). It also aligns with growing calls for harmonization, including most recently by the B7 community, which is tasked with consolidating the interests of the business community and developing concrete and actionable recommendations to the G7 leadership. 

• A new era begins in carbon accounting as ISO and GHG Protocol agree to harmonize their existing portfolios of GHG standards and to co-develop new standards for GHG emissions measurement and reporting
• Until now, GHG standards have been developed separately with varying scopes and verification guidance. The new ISO–GHG Protocol partnership, announced today, represents a fundamental shift toward integration and co-development, enabling users to rely on a coherent framework and reducing potential confusion in the market
• The partnership will produce a common global language for emissions accounting, which will accelerate progress towards decarbonization
• The development of combined, credible standards for GHG emissions terminology, measurement, and reporting provides a long-awaited, trusted solution for companies, investors, verifiers, auditors and policymakers, and aligns with recent calls for harmonization by both government and companies.